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Author Topic: Long term cold hardy citrus breeding project  (Read 20082 times)

Walt

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Re: Long term cold hardy citrus breeding project
« Reply #125 on: December 26, 2018, 03:29:48 PM »
I've past 40 seedlings from US 852.  Only 3 have been polyembryonic.  From what I read, only about 20 of them should be zygotic.  I'm starting to wonder if all the monozygotic seeds are really zygotic.  Hadyvermont PMed me saying he doubted if all monozygotic seeds are zygotic.  I argued against him, though I was also starting to think the same.  I was arguing mostly put together my best argument and convince myself.
I'm pretty sure I'm geting at least some zygotic seedlings.  Some are unifoliate.  Some have lobed, mitten-shaped leaves.  Some are trifoliate, but the 2 outer leaflets are tiny and hard to see.  Some look like US 852, but might segregate for other traits than leaf shape if I let them mature. 
None are being discarded.  They are too young to be sure of anything yet.  None have more than 7 leaves,  Some are still coming through the ground.  But I'm thinking I might have to find a better way to be sure which are zygotic.

Ilya11

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Re: Long term cold hardy citrus breeding project
« Reply #126 on: December 27, 2018, 03:55:32 AM »
Leaves taste is another way to pinpoint the zygotes.
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Millet

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Re: Long term cold hardy citrus breeding project
« Reply #127 on: December 27, 2018, 04:31:27 PM »
Ilya11, please expand on the taste method for determining a zygote.  What to look for with the taste method.

Ilya11

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Re: Long term cold hardy citrus breeding project
« Reply #128 on: December 27, 2018, 04:45:29 PM »
You compare the taste of seedling leaves to that of the young leaves of mother plant.
Zygotic seedlings generally have another taste ( smell, degree of bitterness) than nucellar seedlings, that are closer to the fruit variety.
« Last Edit: December 27, 2018, 04:48:28 PM by Ilya11 »
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SoCal2warm

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Re: Long term cold hardy citrus breeding project
« Reply #129 on: December 27, 2018, 05:46:28 PM »
I'm starting to wonder if all the monozygotic seeds are really zygotic.  Hadyvermont PMed me saying he doubted if all monozygotic seeds are zygotic.  I argued against him, though I was also starting to think the same.
It probably depends on the variety, I am guessing.
I'm pretty sure monoembryotic seeds can be nucellar.

It's a good way to help separate them out, but may not completely separate out the zygotic from nucellar.

Obviously if you have 100 seedlings and can't grow them all out, and you are only looking to keep the zygotic ones, the polyembryonic ones should be discarded. That would at least double or triple the chance that the remaining seeds will be zygotic.

It's all about probabilities and optimizing them.

Example: maybe for one variety, just hypothetically, 70 percent of the monoembryotic seeds will be zygotic, while 10 percent of the polyembryonic seeds will contain a zygotic seedling sprout. It might look something like that.

Regardless of the variety, I think it's still always a good way to help discriminate if you have many more seeds than you want to grow.

I usually write on the labels for my seedlings whether they originated from a polyembryonic seed. That information could help me later.
« Last Edit: December 27, 2018, 05:55:54 PM by SoCal2warm »

Walt

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Re: Long term cold hardy citrus breeding project
« Reply #130 on: January 04, 2019, 01:42:17 PM »
I still have lots to learn. 
Today there is a thread started on brix of citrus.  Brix and pH are 2 things I'll need to be measuring on many fruit.  I knew that, and the brix thread tells how.  Good.  It also warns that brix varies depending on side of tree, which end of the fruit, and more.
And I've learned in the last few days that when a seed has 2 or more seedlings, they may germinate more than 2 weeks apart.  So some of what I thought were monoembryonic aren't.
But I'm not discouraged.  I've wanted to do this for 30 years.  I'm going to stick to it.
I'm very grateful for all I've learned on this forum, and the previous forum.

SoCal2warm

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Re: Long term cold hardy citrus breeding project
« Reply #131 on: January 09, 2019, 03:20:33 PM »
N1tri seedling
(C. ichangensis x trifoliate)


911311

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Re: Long term cold hardy citrus breeding project
« Reply #132 on: January 11, 2019, 10:53:20 PM »
gone
« Last Edit: January 12, 2019, 08:22:18 PM by 911311 »

SoCal2warm

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Re: Long term cold hardy citrus breeding project
« Reply #133 on: January 12, 2019, 12:25:04 AM »
One of the (few) advantages of trying to grow in the PNW is that the temperatures remain really cool (much too cold for citrus to grow) for nearly half the year, so that means there's no danger of leaving dormancy before the danger of frost has passed.
Although we did have some freak unusual weather in the 2017-2018 Winter, with a highly unusual snow in early November and then the temperature never dropping below freezing the entire month of December, then afterwards there was actually a really warm period in early March. (This is far from typical though)

SoCal2warm

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Re: Long term cold hardy citrus breeding project
« Reply #134 on: January 12, 2019, 02:09:22 AM »
kumquat x C. ichangensis
seeds germinating



SoCal2warm

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Re: Long term cold hardy citrus breeding project
« Reply #135 on: January 12, 2019, 03:41:29 AM »
For me, this is a little bit deceptive result and proves that even for a single gene trait you need more than 2 backcroses and 30 years of breeding in order to  get rid of nasty taste of Poncirus fruits.
That's why it may be better to start from already existing more edible hybrids like N1tri, US 852, and Dunstan citrumelo.
In the case of Thomasville citrangequat I virtually didn't detect any off taste at all and it was almost like calamondin or orange in flavor.

Ilya11

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Re: Long term cold hardy citrus breeding project
« Reply #136 on: January 12, 2019, 03:43:24 AM »
911311,
I am not sure to understand what do you mean by dormancy? How can you define it from what can be observed?
Absence of the new growth?
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                       Ilya

Radoslav

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Re: Long term cold hardy citrus breeding project
« Reply #137 on: January 12, 2019, 06:53:00 AM »
911311,
I am not sure to understand what do you mean by dormancy? How can you define it from what can be observed?
Absence of the new growth?

I have a a feeling that 911311 is mixing two things. Dormancy and deciduous behaviour. In fact all my citruses go dormant in temperatures bellow 5°C
celsius, they are in some level of hibernation, no grow, no water consumption.
« Last Edit: January 12, 2019, 06:56:16 AM by Radoslav »

Citradia

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Re: Long term cold hardy citrus breeding project
« Reply #138 on: January 12, 2019, 07:38:52 AM »
911311, in my opinion, cold hardy citrus do go dormant or asleep over winter and where I live, they drop their leaves every winter if not protected from freezing temps all winter. However, they are quicker to wake up and start putting out spring growth before the apples and peaches when we start having highs in the 60’s F for a few weeks in February and March. If the apples or plums or apricots are blooming in March and then we get a freeze in the teens, which happens almost every year here, the bloom of plum and apricot are destroyed but the apples and crabapple bloom survive and peach blossom survive if only gets into low twenties; however, if the citranges start putting out growth/ break dormancy, during a hard spring freeze, they die down from 10 feet tall to two feet tall or die to the roots or die completely. Citrus do not like freezing temps. Deciduous fruit trees like apples need cold temps in winter to live and thrive as part of their nature. Just because literature says citranges are hardy to 5 degrees doesn’t mean your rusk citrange will grow to 20 feet high and be strong and healthy and fruitful in a climate zone that sees 5 degrees every winter. At 5 degrees over night and below freezing for days, the citranges die to ground even though “dormant “but may “survive “ by coming back from the roots sometime in May or June.

eyeckr

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Re: Long term cold hardy citrus breeding project
« Reply #139 on: January 12, 2019, 04:54:55 PM »
+1 to Citradia's post above. Well said. I have the same observations with much of the cold hardy citrus that I have tried. For citrus, zone hardy can often be whittled down to mean zone survivor and not necessarily zone happy. Also the current growth state, maturity, size of the tree, diameter of the trunk, rootstock, lead up to the cold events all play a big part on if a particular variety will make it through each winter.

Millet

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Re: Long term cold hardy citrus breeding project
« Reply #140 on: January 12, 2019, 08:11:51 PM »
Certain aspects of citrus flower development derive from the nature of citrus as a tropical/subtropical evergreen which, unlike deciduous fruit trees, does not have true dormancy.  Deciduous fruit trees form flower buds during early summer. These flower buds complete their development prior to the onset of winter dormancy and appear to be ready by the fall for the burst and bloom of the following spring.  In citrus, flower bud differentiation starts during the winter and moves without interruption towards floral development and bloom. The one notable exception is Poncirus trifoliate, a monospecific genus.  Poncirus species has scale protected flower buds which are initiated during summer. Bloom occurs in early spring, on leafless branches which have completely shed their characteristic trifoliate leaves at the beginning of winter. (Biology of Citrus)

SoCal2warm

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Re: Long term cold hardy citrus breeding project
« Reply #141 on: January 12, 2019, 08:19:09 PM »
I may try to cross Taitri with Oroblanco grapefruit.

(appropriate since Taitri is tiwanica lemon x trifoliate, and tiwanica is really like a sour orange in ancestry, with pomelo-type as far as genetics go)
« Last Edit: January 12, 2019, 08:21:15 PM by SoCal2warm »

Florian

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Re: Long term cold hardy citrus breeding project
« Reply #142 on: January 13, 2019, 06:28:02 AM »
The one notable exception is Poncirus trifoliate, a monospecific genus.  Poncirus species has scale protected flower buds which are initiated during summer. Bloom occurs in early spring, on leafless branches which have completely shed their characteristic trifoliate leaves at the beginning of winter. (Biology of Citrus)

I wonder if that also applies for Poncirus polyandra, the other known species of this genus, which appears to be less coldhardy?

Ilya11

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Re: Long term cold hardy citrus breeding project
« Reply #143 on: January 13, 2019, 10:09:08 AM »
Common pot with seedlings of SwampLemonXC.ichangensisIVIA358 cross

Best regards,
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Jloup27

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Re: Long term cold hardy citrus breeding project
« Reply #144 on: January 13, 2019, 06:34:48 PM »
Beaucoup :)

Florian

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Re: Long term cold hardy citrus breeding project
« Reply #145 on: January 14, 2019, 02:34:29 AM »
Common pot with seedlings of SwampLemonXC.ichangensisIVIA358 cross



Very cool!

Ilya11

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Re: Long term cold hardy citrus breeding project
« Reply #146 on: January 14, 2019, 04:15:37 AM »
Beaucoup :)
Rather poor germination rate, from 5 pollinated flowers I got 178 fully developed seeds, after one month of germination at 27C in perlite, only 72 of them are germinated, that is very unusual. Nevertheless, more than half are hybrids by appearance.
Best regards,
                       Ilya

Jloup27

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Re: Long term cold hardy citrus breeding project
« Reply #147 on: January 14, 2019, 01:36:23 PM »
Did you use Citrus ichangensis ivia for the mother? Hybrids are si trifoliate.

Ilya11

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Re: Long term cold hardy citrus breeding project
« Reply #148 on: January 14, 2019, 01:59:00 PM »
The fruit parent was Swamp Lemon.
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                       Ilya

Walt

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Re: Long term cold hardy citrus breeding project
« Reply #149 on: January 14, 2019, 04:19:41 PM »
Keep us up to date about this cross.  I am excited to know it exists now.

 

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